Page:On the Various Contrivances by Which British and Foreign Orchids are Fertilised by Insects, and on the Good Effects of Intercrossing.djvu/66

From what I had myself previously observed, I was led to examine carefully the female organs of C. tridentatum, callosum, and saccatum. In no case was the stigmatic surface viscid, as it is in all other Orchids (except was we shall see in Cypripedium), and as is indispensable for the securing the pollen-masses by the rupture of the caudicles; I carefully looked to this point both in young and old flowers of C. tridentatum. When the surface of the stigmatic chamber and of the stigmatic canal of the above-named three species is scraped off, after having been kept in spirits, it is found to be composed of utriculi, with nuclei of the proper shape, but not nearly so numerous as with ordinary Orchids. The utriculi cohere more together and are more transparent; I examined for comparison the utriculi of many kinds of Orchids which had been kept in spirits, and in all found them much less transparent. In C. tridentatum, the ovarium is shorter, much less deeply furrowed, narrower at the base, and internally more solid than in the Monachanthus. Again, in all three species of Catasetum the ovule-bearing cords are short; and the ovules present a considerably different appearance, in being thinner, more transparent; and less pulpy than in the numerous other Orchids examined for comparison. They were, however, in not so completely and atrophied condition as in Acropera. Although they correspond so closely in general appearance and position with true ovules, perhaps I have no strict right so to designate them, as I was unable in any case to make out the opening of the testa and the included nucleus; nor were the ovules ever inverted.

From these several facts, namely,—the shortness, smoothness, and narrowness of the ovarium, the shortness of the ovule-bearing cords, the state of the ovules themselves, the stigmatic surface not being viscid, the empty condition of the utriculi,—and from Sir R. Schomburgk never having seen C. tridentatum producing seed in its native home, we may confidently look at this species, as well as the other two species of Catasetum, as male plants.

With respect to Monachanthus viridis and Myanthus barbatus, the President and officers of the Linnæan Society have kindly permitted me to examine the spike bearing these two flowers, preserved in spirits, and